Look for Judith, preferably during the side quest the Naturalist, at the Forester Homestead in Crestwood (southeast of Caer Bronach and south by southwest from the Three Trout Farm Inquisition Camp. Her farm is also the location of one of Crestwood's three astrariums. She will mention a wyvern, and upon inquiring further, the Inquisitor learns that she could use the wyvern's liver for some rat poison if someone would only kill the beast.
The path will eventually lead to a hidden pond, which is home to several wyverns (two at level 11 and a larger one at level 14 or 15; all three are elite ranked). Killing the largest, by provoking and luring it away from the flock with ranged or magic attacks, is the only one needed to satisfy Judith's request. Loot the wyvern and return to Judith for the reward.
Completing the quest yields:
Killing the largest wyvern yields:
- The wyverns have a greater resistance to electricity and are vulnerable to cold damage.
- It is possible to kill the wyvern before obtaining the quest. If this happens, it still can be completed by talking to Judith afterwards.
- The wyvern may not spawn if the main quest What Pride Had Wrought is completed prior to completing the quest. The quest marker will remain if already acquired at this point.